ok so im trying to open up my car going up a steep hill i am getting a thing where when my foot is on the throttle at exactly the same position and the engine seams to cut out and then accelerate again more than once. wondering what kind of problem this is or if it is a problem at all. its kind of weird but it seams that the cars engine simply wont accelerate, and at other times it seams to kick in when it wants. i need this problem diagnosed because i still have not flashed the stage one map. just need some advice, im hoping a new tune would help but am not sure. thanks in advance.

so u guys think its some type of leak? I just had the car in for a full tune up, and it didnt help at all. I would think my mech would have checked all that stuff. it ran a little better the first week or so. i was running a perrin sri without a tune for a while, (it did the same thing before and after the intake swap) and swapped in a cobb intake that supposedly doesnt tneed a tune and i figured this would help but didnt either. !Cry!

Can't say that's it for sure but, its somewhere to start. You can also try resting your ecu by disconnecting the battery. Its hard to say since you sound like your not sure that there really is a problem or not. Just letting you know where most power loss problems come from and, its usually a leak.

yeah im pretty sure my mech found no leak issues, this is the first turbo car i have owned and there is a significant cut out when i gun the throttle. especially up hill. it will go and then stop then go again even when my foot is at the same position the whole time. im not sure whaqt happens after that beczause i usually let off before i get into any issues. it just feels like the car doesnt accelerate at all. i am probly going to bring it in soon. if anyone has any info on this issue it would be cool!

Yikes, it could be the clutch?
I've been having a similar problem for quite some time. Always worsens after I've been driving for a while. However, some days it does it as soon as I start it up, or not at all if I'm just driving around town.
If I turn the car off and on again it will go away, but eventually come back.
I have talked to numerous people about this and have had conjectures of anything from a dirty MAF, to a vacuum leak. Some people had told me it could be the boost solenoid. I was thinking it could be the TPS.
It's nerve wracking when it happens, because it seems like the car is dying. It's frustrating, because I have had this issue for over a year and have not been able to pin point the issue.
Sorry to reopen this clearly old thread, but I'd really like to get as close to an expert opinion as possible. So if there are any professional mechanics on here. Please give me your input I will be extremely grateful.
Everyone, please don't post opinions or guesses. I know it's hard to diagnose without the car in front of you, but this sort of issue obviously has affected other people's cars.
If you have had this problem, or one similar how did you fix it?

I solved my problem by simply cleaning the MAF sensor. after cleaning the maf sensor the car drove amazingly better. if I were you i would do a data log. before i had that problem the log showed problems. then shortly later (after the bogging and hesitation) i found that the car actually started bucking. also after the cleaning the datalogs went back to normal. but anyway hope this helps.

that's great that said company makes them, but where do you purchase it IN JAPAN?!?!
Anyway, I finally found some on amazon. the big issue was it isn't referred to as a Mass Airflow Sensor in japanese, just an Airflow Sensor.
The stuff I bought is made by Kure. I didn't see it at any auto parts stores though.